Surely God loves those who fight in His cause in full formations as though they were a compact wall.
4
Tafseer
'Abdullāh Ibn 'Abbās / Muḥammad al-Fīrūzabādī
تفسير : then he encouraged them to strive in his way, saying: (lo! allah loveth those who battle for his cause) in his obedience (in ranks, as if they were a solid structure) like a cemented block.
Jalāl al-Dīn al-Maḥallī
تفسير : indeed god loves, he assists and honours, those who fight for his cause in ranks (saffan is a circumstantial qualifier, in other words [understand it as] sāffīna), as if they were a solid structure, with all of its parts compacted together, firm.